The following lyric line from Billy Joel's: "New York State of Mind" has always had me puzzled, so I'm hoping someone here can explain to this west coast yokel the actual meaning of it.

"I'm taking a Greyhound on the Hudson River Line"

I assume this refers to a Greyhound bus, right? Does the 'Hudson River Line' refer to a boat? If so, is this a ferry boat line which a Greyhound bus can board?

Thanks, - Scott